<!Doctype html>  
<html lang="en">  
<head>  
  <meta charset="UTF-8">  
  <title>Window对象-Screen对象</title>  
</head>  
<body>  
<input id="demo1" type="button" value="显示屏幕信息" />
<script type="text/javascript">
    document.getElementById("demo1").onclick=function(){
        alert(
            "屏幕信息：\n"+
            "分辨率："+screen.width+"×"+screen.height+"\n"+
            "可用区域："+screen.availWidth+"×"+screen.availHeight
        );
    }
</script>
</body>  
</html> 